1. Technical Field of the Invention
This invention relates to a process for the preparation of predominantly linear polyethylenepolyamines from ethylenediamine and monoethanolamine in the presence of unique catalyst compositions prepared from the reaction product of a minor amount of phosphonitrillic acid with titania.
2. Prior Art
Heretofore, polyethylenepolyamine compounds such as diethylenetriamine, triethylenetetramine and the higher homologs have been produced by the reaction of an alkyl halide such as ethylene dichloride with an amine such as ammonia or ethylenediamine at elevated temperatures and pressures. Normally, relatively high yields of predominantly non-cyclic polyethylenepolyamine compounds are obtained from this process with varying yields of heterocyclic amines. The large amounts of energy required to produce the reactants as well as the difficult separation procedures required to recover the more valuable linear polyethylenepolyamines diminish the usefulness of the ethylene dichloride process. The hydrohalide salts of ammonia and the polyethylenepolyamine products must also undergo difficult and time consuming caustic neutralization to yield the free polyethylenepolyamines.
It has heretofore been known that phosphates can be used to catalyze reactions to produce predominantly heterocyclic rather than linear products. Thus, U.S. Pat. No. 3,297,701 teaches the use of aluminum phosphate to catalyze the reaction of ethanolamines and polyethylenepolyamines to yield cyclic compounds. U.S. Pat. No. 3,342,820 discloses the use of aluminum phosphate for the preparation of heterocyclic compounds such as triethylenediamine. As another example, U.S. Pat. No. 4,103,087 also discloses the use of aluminum phosphate catalysts for producing heterocyclic product compounds.
More recently, investigators have found that more linear products can also be obtained in a catalyst conversion. Johnson et al. U.S. Pat. No. 4,463,193 and U.S. Pat. No. 4,578,517 are directed to the reaction of an alkanolamine with an alkyleneamine and ammonia in the presence of a catalytically effective amount of a group IIIB metal acid phosphate to give primarily noncyclic polyalkylene polyamine products. Thus, in Table 4 of U.S. Pat. No. 4,463,193, Johnson et al. disclose the reaction of monoethanolamine with ethylenediamine and ammonia using catalysts such as lanthanum acid phosphate and praseodynium acid phosphate at conversions of about 11 to 43% of monoethanolamine to give a noncyclic selectivity of about 67% to 92%. In Ford et al. U.S. Pat. No. 4,503,253, phosphoric acid incorporated onto an inert support (silica) was used as a catalyst and in Table 1 of the patent, use of this type of catalyst was shown to provide monoethanolamine conversions of 34% to 68% with a selectivity to noncyclics of 62% to 86%.
European patent application No. 0,073,520 dated August 31, 1982 for Ford and Johnson disclosed that the reaction of monoethanolamine with ethylenediamine and ammonia can be catalyzed with acidic metal phosphates, phosphoric or phosphorous acid or their anhydrides and alkyl or aryl esters (e.g., boron phosphate, ferric phosphate, aluminum phosphate, etc.). U.S. Pat. No. 4,314,083 discloses the reaction of ethylenediamine with monoethanolamine to prepare noncyclic polyalkylenepolyamines using, as a catalyst, a salt of a nitrogen or sulfur-containing compound.
In inventions originating in our laboratories, Brennan et al. in U.S. Pat. No. 4,036,881 discloses the use of phosphorus-containing catalysts to catalyze the reaction of ethylenediamine with monoethanolamine. Excellent results were obtained when the reaction was conducted in an autoclave. However, when the phosphorus compound was supported on silica or diatomaceous earth, good results were obtained only at comparatively low conversions. Brennan et al. U.S. Pat. No. 4,044,053 is also relevant in this regard. Brennan U.S. Pat. No. 4,448,997 is directed to an alumina phosphate-type catalyst composition wherein the novel feature is the method of preparing a catalyst from alumina phosphoric acid, ammonium hydroxide and water. Excellent results were obtained using a catalyst of this nature in batch-type reactions.
More recently, Vanderpool and co-workers in a series of U.S. patents (U.S. Pat. No. 4,540,822 issued Sept. 10, 1985; U.S. Pat. No. 4,578,518 and No. 4,578,519 issued Mar. 23, 1986; U.S. Pat. No. 4,584,406 issued Apr. 22, 1986 and U.S. Pat. No. 4,588,842 issued May 13, 1986) have disclosed that the reaction of monoethanolamine with ethylenediamine to provide essentially noncyclic polyethylenepolyamine reaction products can be effectively promoted with catalysts composed of a minor amount of phosphorus thermally, chemically bonded to a group IVb metal oxide support such as titania or zirconia. Also, in U.S. Pat. No. 4,555,582 issued Nov. 26, 1983 and U.S. Pat. No. 4,524,152 issued June 18, 1985, Vanderpool used a zirconium silicate catalyst to promote this reaction.
In addition, Vanderpool U.S. Pat. No. 4,540,822 issued Sept. 10, 1985 discloses a process for making essentially linear polyethylenepolyamines by reacting monoethanolamine with ethylenediamine in the presence of a catalyst composed of a minor amount of phosphorus thermally, chemically bonded to a group IVb metal oxide support wherein the catalyst is periodically regenerated. In Vanderpool et al. U.S. Pat. No. 4,609,761 which issued Sept. 2, 1986, a catalyst for this reaction is disclosed wherein a trialkyl phosphate or a trialkyl phosphite is initially deposited on titania as a source of phosphorus, and in Renken U.S. Pat. No. 4,612,397 which issued Sept. 16, 1986, a diammonium hydrogen phosphate is used as a source for the phosphorus in preparing the catalyst.
Zimmerschied et. al. U.S. Pat. No. 2,921,081 discloses catalysts for use in the conversion of olefins that are prepared by reacting a zirconium halide with a designated class of phosphoric acids.
Rylander et. al. U.S. Pat. No. 2,824,073 is concerned with the manufacture of a titanium-phosphoric acid catalyst that can be prepared by mixing titania with triphosphoric acid to form a doughy mixture which is thereafter dried and heated.
The text, "Refractories", by F. H. Norton (McGraw-Hill Book Company, Inc., 1949) in pages 318 and 319 discloses hafnium oxide, titanium oxide and zirconium oxides as well-known refractories.